This invention relates to scooters, and, more particularly, to a scooter that includes a drive mechanism actuated by the scooter passenger.
A scooter generally is comprised of a rear wheel and a steerable front wheel joined by a chassis which supports a platform on which the rider stands. In its simplest form, the scooter is propelled by the rider using one foot to push rearwardly against the pavement in a one-leg stride, while the other leg supports most of the rider's weight on the platform. Although the rider can alternate the use of either leg to avoid fatigue, it is recognized that this form of propulsion is tiresome. Moreover, it is inefficient, in that increasing speed requires that the propelling foot be pushed rearwardly with concomitantly increasing speed to gain any propulsive effect. At relatively low speeds (compared to a bicycle), the rider can gain little acceleration by continuing to stride, even while the effort becomes arduous.
Because of this and other problems inherent in scooter designs, various scooter drive mechanisms have been devised in the prior art. For example, a pedal mounted on the platform may be connected to a rack gear that drives a pinion gear on the rear wheel shaft, whereby reiterative pedal depression may drive the rear wheel and produce forward motion. Likewise, the pedal may be joined to a drive link that is connected to a crank or eccentric on the rear wheel shaft to convert the oscillating motion of the pedal to rotational drive motion at the rear wheel. Various improvements to these concepts include compound gear drives, dual pedals, chain drives, and other mechanisms known in mechanical engineering.
One problem intrinsic to these designs is that their mechanisms generally extend below the scooter platform, so that the platform remains available to accommodate the feet of the rider. However, by projecting below the platform, the drive mechanisms reduce the ground clearance and invite the possibility of collision between the drive mechanism and relatively small obstacles on the pavement. Moreover, the ability to negotiate bumps, holes, curbs, and uneven pavement is reduced. Although the platform may be supported higher to accommodate the drive mechanism therebelow with sufficient ground clearance, this expedient raises the center of mass of the rider, which may cause instability, and renders stepping on and off the scooter platform more problematic.